Refrigerating apparatus



Aug. 23, 1938. n. R. cANDoR REFRIGERATING APPARATUS 2 Sheets-Sheet 1Filed April 30, 1934 Aug. 23, 1938. R. R. cANDoR REFRIGEHATING APPARATUSFiled April 30, 1934 2 Sheets-Sheet 2 Patented Aug. 23, 1938 UNITEDSTATES PATENT OFFICE REFRJGERATING APrAaATUs Robert R. Candor, Dayton,Ohio, assigner to General Motors Corporation, Dayton,` Ollio, acorporation of Delaware- Application April 30,1934, serial 110,123,113

1v claims. t (ol. s2-115) v 10 invention will be apparent from thefollowing description reference being had to the accompanying drawings,wherein a preferred form of the present invention is clearly shown.

In the drawings: l

Fig. 1 is a diagrammatic representation of an apparatus embodyingfeatures of my invention;

Fig. 2 is a view somewhat similar to a portion of the apparatus shown inFig. 1, showing a slightly modified form; f

` 20 Fig. 3 is a view, partly in cross section, and

partly diagrammatic of the application o f my invention to a railway caror the like; l

Fig. .4 is a diagrammatic plan view of a carto which my invention may beapplied: g i Fig. 5 is a plan view of the top of the air conditionershown in Fig. 3; and

Fig. 6 is an enlarged vertical cross-sectional A view of the top of theair conditioner shown in Fig 3.v

vai) 4`i'i'ccording to this invention, the efficiency of the usualmultiple vcylinder compressor used for .air conditioning is greatlyenhanced by a slight and inexpensive change in the valves, and withoutthe necessity of changing the bore or volumetric v capacity of thevarious cylinders: By this invention, air may be conditioned byevaporators which gradually decrease in temperatureand the varionscylinders may be coordinated -into the air conditioning scheme withoutthe necessityof changing the main parts of the compressor. Usually amere change in the valving structure of the compressor is sufficientto'accomplish this end. f

As shown in Fig. 1, air to be conditioned which may come 4from theoutside atmosphere, or from an enclosure or both may be caused to flowin the form of a stream through a casing Ill by any suitable means asthe motor driven fan Il and the conditioned air is discharged. into theen-y closure. The stream of air first encounters the relatively warmevaporator l2 and then the relatively cold evaporator I2. Thus a certainportion of the heat from the air is removed therefrom at arelativelyhigh refrigerant pressure or temperature in evaporator I2 andthe last traces of heat g5 are removed by a relativelyY low refrigerantpressure or temperature in evaporator Il. The evaporated refrigerantfrom these evaporators is introduced into the compressing'and condensingmeans at the proper stages of compression to obtain full advantage of myinvention. Thus a compressor i4 is provided having a plurality ofcompressing chambers Il and ,i6 which may be of substantially the samevolumetric displacement. These chambers are provided with pistons I1 andIl of substantially the same diameter and which are reciprocated byeccentrics on the shaft I9- having substantially the same throw. Thecheck valves 20 and 2I are constructed to cause the flow of refrigerantvapor into the crankcase 22 and the valves 2l and 24 are constructed tocause'a flow of refrigerant vapor from the crankcase' 22. The suctionoutlet of the relatively cold evaporator i2 is connected by means of theline '25 with the intake 28 of the compressing chamber Iii from whichthe partially compressed refrigerant vapors are discharged intocrankcase 22. The suction outlet of thev evaporator I2 is connected bythe line 21 with the crankcase 22. Here the vapors from evaporator I2are commingled with the partially compressed vapors from evaporator I2and enters the compression chamber I5. The discharge from thecompressing chamber i5 is connected by the line 2l with the condenser 2lwhich is provided with the liquid receiver It. From this receiver.liquefied refrigerant flows through the line 2l through branches 32 and33I to the evaporators I2 and I2 respectively for reevaporation.

.The evaporator i2 is provided'withan automatic expansion valve .2lwhich tends to feed liquid refrigerant into the evaporator when thepressure is reduced below a predetermined limit.l

However, this action is modified by a thermostatic bulb 25 placed nearthe refrigerant outlet of i evaporator I2. This thermostatic bulbthrottles the valve 24 when the liquid refrigerant .tends to flow pastthe-evaporator outlet into the line 21.. A valve 2B, similarto the valve24, is placed at the inlet of the evaporator I2. A thermostatic bulb 31,similar to the bulb 2i, is placed near the outlet of the evaporator i3and throttles the valve 26 in the same manner.

As shown in Fig. 1. evaporated refrigerant from the evaporator I3 flowsinto the intake 22` of the compressing chamber. it. It then flows pastthe valve 2U and is forced on the upward stroke of the piston Il into`the crankcase 22. From thence it flows through the valved intake 22 ofthe compressingI chamber Il lon the ,downward stroke of the piston i1,and is forced through the valve 2l into the outletl 38 on the up strokeof the piston I1. The refrigerant then ows to the condenser 29 where itis liquefied and is re-intrbduced into the evaporators through theexpansion valves 34 and 36. Evaporated refrigerant from the warmevaporator I2 flows through the line 21 to th'e crankcase 22 where it ismingled with the partly compressed refrigerant from the evaporator I3and enters therewith into the compression chamber I5', under thecompressing action of the piston I1, and ows to the condenser 29 forreuse in the evaporator.

Automatic controls are provided. Thus a thermostat 39 may be placedinthe enclosure which is supplied with air from the casing I9. Thisthermostat may operate a snap switch 40 which starts and stops the motor4I which drives the compressor I4. The thermostat 39 may be calibratedto start the motor at a predetermined higher temperature limit and tostop the motor at a predetermined lower temperature limit. The flow ofrefrigerant through one of the evaporators Y may be controlled inaccordance with slightly difship` through the compression chambers.

ferent air conditions. Thus the line 21 may be provided with throttlingvalve 42 which is actuated by a thermostat 43 also placed in theenclosure with the thermostat 39. The thermostat 43 may be calibrated atslightly higher temperature limits. Thus when the temperature in theenclosure drops to a predetermined higher limit,

the valve 42 is throttled and thus a fiow of refrigerant through theevaporator I2 is stopped. If the temperature in the enclosure drops to astill lower predetermined limit, the thermostat 39 stops the compressorI4. Thereafter, if the temperature risesto a predetermined limit, thethermostat -39 starts the compressor I4, and if the temperature rises toa still higher limit, the thermostat 43 opens the valve 42. 'I'hethermostats 39 and 43 may both be dry bulb thermostats or they maybeboth wet bulb thermostats or psychometers, or one may be a dry bulb andthe other a wet bulb thermostat or a psychometer. At the present, it ispreferable to have them both dry bulb thermostats.

In the modification shown in Fig. 2 the valve structure isslightly-modified. Thus the relatively cold evaporator I3 may beconnected by theline with the compressing chamber 5I. 'I'he refrigerantmay enter past the check valve 52 on the down stroke of the piston 53.Refrlgerant may be discharged past the check valve 54 on the -up strokeof the piston 53 and may flow through the passage 55 into the crankcase55 of the compressor. The relatively warm evaporator I2 may be connectedby the line 51 with the crankcase 56. The commingled evaporatedrefrigerant from both evaporators may pass through the check valve 58into the compression chamber 59 on the down stroke of the piston 60.These vapors'may be discharged through the check valve 6I and 'the yupstroke of the piston 60 and may flow through the line 62 of a condensercorresponding `to the condenser 29. The volumetric displacement of thecompressing chambers 5I and 59 may be substantially equal, andtheremainder of the system may be as shown in Fig. 1.

In constructing compressors as shown in Figs. 1 and 2, the usual singlestage multiple cylinder compressors may be used, which are generallyprovided with check valves in the pistons and at the cylinder heads insuch a manner as to cause the flow of refrigerant in parallel relation-By changing the valve structures as shown in Figs.

1 and 2, stage compression may be obtained' which may be coordinatedwith an air conditioning systemto great advantage as described. fWhile.I have described certain features of my invention as particularlyadvantageous with compression chambers of substantially equal volumetricdisplacement these and other features may also be used where thecompression chambers are not thus equal.

The air condi ioning system shown in Figs. 1 and 2 may be ofgeneralapplication and may be used to condition a r or similar gas whereverdesired. One place where it is particularly advantageous and whereelectrical energy is at a premium is on railway cars, such as indicatedin Figs. 3 to 6 inclusive. Thus the car may have a passenger enclosure10. This enclosure may have one or more rows ofl seats 1I and 12, one oneach side of the aisle 13. Between the seats on each row airconditioners 14 may be placed in parallel.v relationship with the longdimension of the seats.I The air conditioners 'I4 may each take the formof a vertically disposed casing 15 which is relatively long inhorizontal cross section and is adapted to fill the spacebetween twoseats, which may be placed back to back as shown in Fig. 8. A motordriven fan 16 may' be placed in the casing together with a. relativelywarm evaporator 11 and a relatively cold evaporator 18. These memberscorrespond to the fan II and evaporators I2 and I3 respectively inFig. 1. Air from the enclosure 10 flows through inlet 19 past therelatively warm evaporator 11 under the impulse of fan 16 and then iiowsthrough a relatively cold evaporator`18 from which it isdiffused intoenf closure 10 in an upward direction through louvers 80 placed in theupper part of. the casing 15. These louvers 80 may conveniently be madeparallel with several of them slanting in one direction 'and several ofthem slanting in the other direction thus to spread the air upwardly andoutwardly over the seats but above the head room of persons occupyingthe seats. A refrigerant compression system substantially as shown inFig. 1 may be placed anywhere in the car. A thermostat 8| may controlthe suction line 82 of evaporator 11 in a manner similar to valve 42 andthermostat 43 in Fig. 1, while a thermostat 83 may control the startingand stopping of the motor, not shown, in a manner similar to theoperation of thermostat 39 in Fig. 1. The motor may be driven from theusual electric storage battery system provided in railway cars or by anyother electric system especially provided therefor, as desired. v

While the form of embodiment of the invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. In combination a relatively warm evaporator, a relatively coldevaporator, compressing means and condensing means connected to withdrawevaporated refrigerant from said evaporators, compress and condense thesame and return condensed refrigerant to said evaporators, saidcompressing means including compressing chambers of substantially theysame volumetric displacement, the suction line from said coldevaporator being connected to the intake of one of said compressingchambers, the discharge from said last named compressing chamber and thesuction line from said warm evaporator being connected to the intake ofanother of said compressing chambers.

draw evaporated refrigerant from said evaporators, compress and condensethe same and return condensed refrigerant to said evaporators, saidcompressing means forming a plurality of com" pressing chambers and acrankcase, the suction line from said cold evaporator being connected totheintake of one of said compressing chambers, the discharge from saidlast named compressing chamber and the suction from said warm evaporatorbeing connected to said crankcase, the intake of another of saidcompressing chambers being connected to said crankcase, and thedischarge from said last named compressing chamber being connected tosaid condensing means.

3. An air conditioning apparatus vcomprising means creating a stream ofair to be conditioned, a relatively warm evaporator and a relativelycold evaporator in thermal exchange relationship with said stream ofair, compressing means and condensing means connected to withdrawevaporated refrigerant from said evaporators, compress and condense thesame and return condensed refrigerant to said evaporators, saidcompressing means including a plurality of compressing chambers,thesuction vline from said cold evaporator being connected to the intake ofone ofsaid compressing chambers, the discharge from said last namedcompressing chamber and the suction line from said warm evaporator beingconnected to the intake of another of said compressing chambers.

`4. An air conditioning apparatus comprising means creating a stream ofair to be conditioned,

a relatively warm evaporator and a relatively cold evaporator in thermalexchange relationship with said stream of air, compressing means andcon-,f`

densing means-connected to withdraw evaporated refrigerant from saidevaporators, compress and condense the same and return condensedrefrigerant to said evaporators, said compressing means forming aplurality of compressing chambers and a crankcase, the suction line fromsaid cold evaporator being connected to the intake of one of saidcompressing chambers, the discharge from said last named compressingchamber and the suction from said warm evaporator being connected tosaid crankcase, theintake of another of said compressingchambers beingconnected to said crankcaseand the discharge from said last namedcompressing chamber being connecte'd to said condensing means.

5. An air conditioning` apparatus vcomprising means creating a stream ofair to be conditioned,

a relatively warm evaporator and a relatively cold evaporator in thermalexchange relationship with said stream ofair; compressing means andcondensing means connected towithdraw evaporated refrigerant from saidevaporators, compress and condense the same and return condensedvrefrigerant to said evaporators, means controlling the operation' ofsaid compressing means in accordance with airconditions and meansthrottling the flow of refrigerant in one of said evaporators 'inaccordance with other air conditions.

[6. An air conditioning apparatus comprising means creatinga stream ofair to be conditioned. a relatively warmevaporator and a relatively coldevaporator in thermal exchange relationship with said stream of air,said evaporators being in series relationship in said stream of air,compressing means and condensing means connected to withdraw evaporatedrefrigerant from said' evaporators, compress and condense the same andreturn condensed ref erant to said evaporators, said vcompressing meansincluding a plurality of compressing chambers, the suction line fromsaid cold evaporator being connected to the intake of one of saidcompressing chambers, the discharge from said` last named compressingchambers and the suction line from said warm evaporator being connectedto the intake of another of said compressing chambers.

'7. An air conditioning apparatus comprising means creating a stream ofairto be conditioned, a relatively warm evaporator and a relatively coldevaporator in thermal exchange relationship with v said stream of air,said evaporators being in series relationship in said stream of air,compressing means and condensing means connected to withdraw evaporatedrefrigerant from -said evaporators, compress and condense the same andreturn condensed refrigerant to said evaporators, said compressing mansincluding ai plurality of compressing chambers, the suction line fromsaid cold evaporator being connected to the intake of one of saidcompressing chambers, the discharge from said last -named compressingchamber and the suction line from said warm evaporator being connectedto the intake of another of said compressing chambers means controllingthe operation of said compressing meansin accordance with airconditions, and means throttling the flowof refrigerant in one of saidevaporators in accordance with air conditions.

8. An air conditioning apparatus comprising 4an enclosure, meanscreating a stream of' air to be conditioned for said enclosure, arelatively -Warm evaporator and a relatively cold evaporator in thermalexchange relationship with said stream of air, compressing means andcondensing means connected to Withdraw evaporated refrigerant from saidevaporators, compress and condense the same and return condensedrefrigerant to said evaporators, means controlling the operation of saidcompressing' means in accordance with air conditions in said enclosureand means throttling the flow of .refrigerant in one of said evaporatorsin accordance with other air conditions .in said enclosure.

9. A car having a passenger enclosure having a row of seats, an airconditioning apparatus for said enclosure comprising means creating astreamof air to be conditioned between two of said seats,v a relativelywarm evaporator and a relatively cold evaporator in thermal exchangesaid seats evaporating means in thermal exchange Arelationship with saidstream of air, compressing and condensing means connected to withdrawe'vaporated refrigerant from saidI evaporating means, compress 'andcondense. the same and return condensed refrigerant to. saidevaporati'ng means, and means controlling vthe operation of relationshipwith said lstreamof air, compressing said compressing means inaccordance with cony ditions in said car.

1l. A car having a passenger enclosure having said enclosure disposedbetween two seats commeans in thermal exchange relationship with saidstream of air. A

12. A car having two rows of seats, one on each side of an aisle, an aircooler on one side of said' aisle between two seats and an air cooler onthe other side of said aisle arranged to cooperate with the first namedcooler to create a circulation of conditioned air within the car.

13. A car having two rows of seats, one on each side of an aisle, an aircooler on one side of said aisle between two seats and an air-cooler onthe other side of said aisle said coolers discharging cooled airupwardly and cooperating .to create a current of conditioned air withinthe car.

414. The method of conditioning air which Acomprises ilowing air in astream. thermally contacting said stream with a volatile refrigerant ina rst zone maintained at a relatively warm evaporating temperature,thermally contacting said stream with a volatile refrigerant in a secondzone maintained at a relatively cold evaporating temperature,compressing refrigerant vaporsl from said second zone in a firstcompressing stage, mixing the vapors thus compressed with refrigerantvapor from said first zone and compressing the commingled vapors,condensing the vapors thus compressed and re-evaporating them in saidzones.

15. The method of conditioning air which comprises flowing air in astream, thermally contacting* said stream with a volatile refrigerantin' a Afirst zone maintained at a relatively warm evaporatingtemperature, thermally contacting 4said stream with a volatilerefrigerant in a second zone maintained at a relatively cold evaporatingtemperature, compressing refrigerant vapors fron a row of seats, an airconditioning apparatus for u commingled vapors, condensing the vaporsthus compressed, reevaporating them in said zones, controlling theevaporation in one of said zones independently of the other zone inaccordance with air conditions and starting and stopping thecompressionof refrigerant vapors in accordance with air conditions.

16. In combination, a relatively warm evaporator. a relatively coldevaporator, compressing 'means and condensing means connected towithdraw evaporated refrigerant from said evaporators, compress andcondense the same and return condensed refrigerant to said evaporators,said compressing means having substantially the same volumetricdisplacement for each evaporator, the suction line from said coldevaporator being connected to the intake of Aone of said compressingmeans, the discharge from said last named compressing means and thesuction line from said warm evaporator being connected to the intake ofanother of said compre ing means.

17. In-a combination, relatively warm evaporator, a relatively coldevaporator, compressing means and condensing means connected to withdrawevaporated refrigerant from said evaporators, compress and condense thesame and return condensed refrigerant to said evaporators, saidcompressing means having only two compressing chambers both of whichhave substantially the same volumetric displacement, and a crankcase,the suction line from said cold evaporatorqbeing connected to the intakeof one of said compressing chambers, the discharge from said last namedcompressing chamber and the suction from said warm evaporator beingconnected to said crankcase, the intake of another of said compressingchambers being connected to said crankcase, and the discharge from saidlast named compressing chamber being connected to said condensing means.

,ROBERT R. CANDOR.

